Introduction to Human Body and Chemistry of Life

Anatomy

The study of body structure. (Ex: bones, organs, tissues)

Physiology

The study of body function. (Ex: how the heart pumps blood)

Levels of organization in the body

Chemical - atoms, molecules; Cellular - basic unit of life; Tissue - group of similar cells; Organ - 2+ tissues, specific function; Organ system - group of organs working together; Organism - whole body.

Major characteristics of life

Movement, Responsiveness, Growth, Reproduction, Respiration, Digestion, Absorption, Circulation, Assimilation, Excretion.

Metabolism

All chemical reactions in the body that keep you alive.

Catabolic reactions

BREAKS down (Ex: digestion)

Anabolic reactions

BUILDS up (Ex: muscle growth)

Major requirements of organisms

Water, Food, Oxygen, Heat, Pressure.

Homeostasis

The body's ability to maintain stability.

Importance of homeostasis

It keeps the internal environment stable, which is needed for survival.

Negative Feedback Loops

Reverses change (Ex: sweating when hot)

Positive Feedback Loops

Increases change (Ex: childbirth)

Major body cavities

Cranial (brain), Spinal/Vertebral (spinal cord), Thoracic (lungs, heart), Abdominopelvic (digestive, urinary organs).

Organs in Cranial cavity

Brain.

Organs in Spinal cavity

Spinal cord.

Organs in Thoracic cavity

Lungs, heart.

Organs in Abdominal cavity

Stomach, liver, intestines.

Organs in Pelvic cavity

Bladder, reproductive organs.

Membranes in thoracic cavity

Pleura (lungs), pericardium (heart).

Membranes in abdominopelvic cavity

Peritoneum.

Major organ systems

Integumentary - skin; Skeletal - bones; Muscular - muscles; Nervous - brain, spinal cord; Endocrine - glands (hormones); Cardiovascular - heart, blood vessels; Lymphatic - lymph nodes; Respiratory - lungs; Digestive - stomach, intestines; Urinary - kidneys, bladder; Reproductive - testes/ovaries.

Functions of Integumentary system

Protection.

Functions of Skeletal system

Support.

Functions of Muscular system

Movement.

Functions of Nervous system

Control.

Functions of Endocrine system

Hormones.

Functions of Cardiovascular system

Transport.

Functions of Lymphatic system

Immunity.

Functions of Respiratory system

Gas exchange.

Functions of Digestive system

Digestion.

Functions of Urinary system

Waste removal.

Functions of Reproductive system

Offspring.

Relative positions

Superior - above; Inferior - below; Anterior (Ventral) - front; Posterior (Dorsal) - back; Medial - toward midline; Lateral - away from midline; Proximal - closer to trunk; Distal - farther from trunk.

Body sections

Sagittal (left/right), frontal (front/back), transverse (top/bottom).

Matter

Anything with mass.

Atoms

Smallest unit.

Compounds

2+ atoms bonded.

Atomic structure

Electrons (in outer shell) determine bonding and reactivity.

Molecular formulas

Shows elements (H₂O).

Structural formulas

Shows bonds.

Main body elements

Carbon, Hydrogen, Oxygen, Nitrogen (CHON).

Importance of CHON

They make up 96% of your body - used in proteins, carbs, DNA, etc.

Trace elements

Needed in very small amounts (Ex: iron, zinc).

Protons

Positive, in nucleus.

Neutrons

Neutral, in nucleus.

Electrons

Negative, orbit nucleus.

Characteristics of Protons

+1 charge, 1 amu.

Characteristics of Neutrons

0 charge, 1 amu.

Characteristics of Electrons

-1 charge, tiny mass.

Types of chemical bonds

Ionic - transfer of electrons; Covalent - sharing of electrons; Hydrogen - weak attraction (Ex: water molecules).

Polar molecules

Unequal sharing (Ex: water).

Nonpolar molecules

Equal sharing (Ex: oxygen gas).

Characteristics of water

Universal solvent, High heat capacity, Cohesion & adhesion, Polar molecule.

Acids

Releases H⁺.

Bases

Releases OH⁻.

Salts

Forms from acid + base reaction.

pH scale

Measures H⁺ concentration; 0-6 = acid; 7 = neutral; 8-14 = base.

Function of buffers

Resist pH changes - help maintain homeostasis.

Macromolecules

Structure + Function: Carbs - Monomer: monosaccharides (Ex: glucose), Polymer: starch, glycogen, Function: energy; Lipids - Monomer: fatty acids, Polymer: triglycerides, Function: energy, insulation; Proteins - Monomer: amino acids, Polymer: polypeptides, Function: enzymes, structure; Nucleic Acids - Monomer: nucleotides, Polymer: DNA, RNA, Function: genetic info.

Dehydration synthesis

Builds molecules by removing water.

Hydrolysis

Breaks molecules by adding water.